In Grindhouse, their crazily funny and exciting tribute to the grimy glory days of 1970s exploitation films, Quentin Tarantino and Robert Rodriguez re-create the junk cinema of their youth with a deftly amused appreciation for its cheeseball squalor. But they also celebrate those films for their accidental B-movie nihilism, their freedom. The low-budget, anything-goes genre movies that sprung up like weeds during the ’70s had a distinct, tasty decadence — a depraved underground allure. Taken as drama, they were glum and listless, often borderline inept, but they weren’t trying to be ”good.” They were vehicles for sensation — for nudity and zombie flesh, for cars screaming down the road with a death-rattle roar — and since sensation was more or less the only thing alive in them, their cruddiness worked in a peculiar way. In the very apathy of their storytelling, they expressed the blasted, what do we do now? hangover of the post-counterculture era; in their promise of cheap thrills, they offered a down-and-dirty escape from that alienation. They were rooted in the action of the moment, and only the moment. They were drive-in rock & roll.

Grindhouse wants to give you a ticky-tacky good time, and does, but it also taps the wild, jagged spasms of aggression that gave those films their primitive outlaw style. In doing so, it summons the most crackerjack pop charge of any movie with Tarantino’s name on it since Pulp Fiction.

Tarantino and Rodriguez have conceived Grindhouse as an old-school, three-hour night at the movies, a trash-heaven double bill complete with scratchy mismatched prints, trailers for unspeakably bad slasher and revenge films (I loved the ones for Machete — ”He just f—ed with the wrong Mexican!” — and the deeply sick Thanksgiving), even that twirling-rainbow ”Our Feature Presentation” fanfare. Growing up in the ’70s, I spent my share of time in grind-house theaters, and I can testify: This is exactly what it felt like. The first movie on the bill is Rodriguez’s Planet Terror, a bottom-of-the-barrel living-dead thriller, set in a present day that feels just like 1974, with zombies that get shot and spurt raspberry Jell-O blood. Rodriguez captures a particular mood of desultory, badly lit gross-out ghoulishness, and he does it with such heightened fanboy exactitude that it’s as if he’d made the Far From Heaven of schlock. He gets the wormy dank images, the slam-lurch editing, the greasy synth score, the leaden early attempts at ”irony.” He also gets the sprawlingly vague disaster-movie narrative (it’s got something to do with toxic green gas and Osama bin Laden) that’s really just a frame for insanely arbitrary mutating-flesh effects, which tend to come out of nowhere anyway. When a title announces there’s a missing reel, it hardly matters: The film cuts to an apocalyptic inferno at a barbecue joint, and it’s as if we’d lost nothing.

The actors don’t miss a beat of badness, which raises a question: Why is this movie so much more fun than the ones it’s copying? In part, because Rodriguez gives it little kinks of hyperbole, like Rose McGowan as a stripper who ends up with a machine gun for a prosthetic leg. But also because Grindhouse, like Ed Wood and Boogie Nights, celebrates how certain low-grade entertainment, viewed in hindsight, looks different now than it did then, since we can see the ”innocence” of its creation — the handmade quality of it — in a world not yet ruled by corporate technology.

Where Planet Terror is an instant classic of deadpan perfection, Death Proof, Tarantino’s crash-and-burn homage to the road-demon genre of Vanishing Point and White Line Fever, is a flawed yet audacious hell-bent head trip. It starts off as Tarantino’s most intricate jam session of trash-talking girls (and their sexy bare feet), only to introduce Kurt Russell as Stuntman Mike, a scarred old TV stunt driver who turns out to be a lot less charming than he looks. Death Proof, in tone, begins as a period piece but then shifts gears to a quartet of contemporary Hollywood women (including Rosario Dawson and Zoë Bell). Their endless jabbering sex talk lands somewhere between the hypnotic and the exhausted, but Tarantino is merely setting us up for the kill: the wildest, rowdiest, most bravura two-car road duel since the grind-house era, which the movie now exhilaratingly brings into our era. You don’t just get off on the speed; you get hooked on the desire for death. The final showdown is sheer brutality, sheer bliss, and sheer primal statement on the new power balance of the sexes. It will leave you laughing, gasping, thrilled at a movie that knows, at long last, how to put the bad back in badass.